1. Field of the Invention
The present invention relates to a toner supplying device used in an image forming apparatus, such as a copier, a facsimile (FAX), a printer, or a multifunction peripheral having multiple functions of these and to an image forming apparatus including the same.
2. Description of the Related Art
In electrophotographic image forming apparatuses, toner as a developer is supplied from a developing device onto a latent image formed on the surface of an image bearer for development, whereby the toner in the developing device decreases. For this reason, the image forming apparatuses include a toner supplying device that supplies toner to the developing device. In the toner supplying device, toner is contained in a toner container that is tubular, that includes a toner discharge opening at an end thereof in its longitudinal direction, and whose inner wall has a spiral groove. The toner container is rotationally driven to convey the toner contained therein in the longitudinal direction along the spiral groove and discharges it from the toner discharge opening. The toner in the toner container may adhere to the inner wall face of the toner container due to the toner ingredients, the environment, and the sheet feeding conditions, and may not be discharged simply by rotational driving and thus remain inside the toner container.
Japanese Laid-open Patent Publication No. 11-109737 discloses a technique in which a driving unit is used to vibrate a toner container to reduce residual toner in the container. Japanese Laid-open Patent Publication No. 2012-141382 discloses a technique in which a unit for applying vibrations to the end (near a toner discharge opening) of a toner container to vibrate the container.
The configuration in Japanese Laid-open Patent Publication No. 11-109737 requires a driving unit for vibrating the toner container, which may lead to an increase in cost or complexity of the layout. The configuration in Japanese Laid-open Patent Publication No. 2012-141382 applies vibrations to the toner container near a toner discharge opening and thus the vibration effect on the whole toner container is small, which does not solve toner discharge failure.
There is a need to reduce toner discharge failure while ensuring low costs and space savings.